If you’ve ever watched a cooking show and wished you could taste the food on screen, scientists may now have the answer.
Thanks to researchers at City University of Hong Kong, it may soon be possible to experience the sensation of taste in virtual reality.
Scientists have developed a lickable VR device that can create ‘adjustable taste’ experiences in a virtual world.
In the future, these strange devices could make food shows like the Great British Bake Off more immersive than ever as viewers taste the food alongside Paul Hollywood and Prue Leith.
The ‘lollipop-shaped taste interfacing systems’ are capable of producing up to nine different flavours.
Currently, that includes sugar, salt, citric acid, cherry, passion fruit, green tea, milk, durian, and grapefruit.
Each of the flavours is created using food-grade flavour chemicals stored inside pouches of agarose gel – a gel usually derived from red algae.
When a voltage is applied to the lollipop, the chemicals rise to the surface of the gel in a liquid which mixes with saliva on the tongue to produce taste.
As virtual and mixed reality become more common, researchers are busy looking for ways to make our virtual worlds more immersive.
Scientists have found ways the recreate the senses of sight, sound, and touch in virtual reality using ‘haptic’ equipment.
Some researchers have even created devices capable of simulating smells within the virtual world using a Smell-O-Vision-like device attached beneath the nose.
However, taste has proven to be the hardest of all the five senses to recreate in virtual reality.
In a paper published in the Proceedings of the National Academy of Sciences, lead author Dr Yiming Liu and their co-authors write: ‘Alongside visual, auditory, haptic, and olfactory sensations, taste significantly influences both the physiological and psychological aspects of human experience.
‘However, the research in the development of taste-generating technologies in VR applications is still in its infancy.’
The researchers’ solution is a device which looks like a plastic lollipop with a series of metal electrodes placed around the edge.
Each of these points contains a package of agarose gel infused with flavour chemicals.
This gel’s unique properties mean that, when no current is being applied, someone licking the device wouldn’t be able to taste anything.
But when a current is applied to the gel, a process called iontophoresis forces the flavour chemicals to rise to the surface.
Now, when someone licks the device, they will be able to taste whatever flavour is being simulated.
If the current is increased, more flavour chemicals are driven to the surface producing a stronger taste.
By adjusting the voltage applied to each of the nine flavour options, the device can simulate an almost endless array of possible tastes.
The researchers also produced VR lollipops with only two or five flavour gels which were able to produce an even more intense taste at the cost of versatility.
To keep the whole setup portable, the researchers made the lollipop as light as possible.
Even when loaded with gels, the device only comes to 15g which is about the weight of an AAA battery.
The researchers write: ‘We report a set of intelligent and portable lollipop-shaped taste interfacing systems covering from two to nine different taste options for establishing an adjustable taste platform in virtual reality (VR), augmented reality (AR), and mixed reality (MR) environments.’
To make the experience complete, the paper also details how the lollipop could be paired with a seven-channel smell simulator.
This device uses scented strips of paraffin wax to create smells which simulate what the user can see in virtual reality.
By combining flavour and smell simulation, scientists can get as close as possible to the real experience of eating.
In their paper, the scientists identify three areas they think would be promising applications for their device.
First, they suggest that the lollipop could be used to remotely deliver a ‘medical gustation assessment’ which is the taste equivalent of an eye test from an optician.
Secondly, Dr Liu says that the device could be used for ‘remote shopping’ which would let users taste food products before they buy them.
Finally, they add that the VR lollipop would likely be useful for uses in ‘mixed reality’ where, for example, a child could explore the flavours of different foods.
The researchers had considered using other methods to produce a simulation of flavour such as electrostimulation which applies a current directly to the tongue in order to trick the body into having a taste sensation.
Previous studies have shown that low-level electrical currents in cutlery or chopsticks can be used to make food taste more salty than it actually is.
However, the researchers ultimately opted to use the gel-based approach since the weaker currents required were deemed to be safer.
The only downside of this approach is that the gels can run out quite quickly.
Currently, the authors say that the digital lollipop can be used for about an hour before the chemical-infused gels shrink to the point of needing to be replaced.
While the range of possible flavours is quite limited for now, going forward the researchers say they will investigate ways of adding more flavour channels and improving how long the device can be used.
